1. Field of the Invention
The present invention relates generally to a portable mobile telephone, and in particular, to a portable mobile telephone with a color display unit.
2. Description of the Related Art
Recently, a portable mobile telephone has been designed to support a VOD (Video On Demand) function, a television broadcasting reception function and a videophone function as well as the traditional voice call function. Such a portable mobile telephone includes a color display unit such as a color LCD (Liquid Crystal Display) to display color images.
An image format for expressing a digital color image includes ‘YUV’ format and ‘YIQ’ format in addition to the traditional ‘RGB’ format used for a color computer graphic and a color television. The ‘RGB’ format expresses a color image with Red (R), Green (G) and Blue (B) components, while the YUV format expresses a color image with one luminance component Y and two color components U and V. The YIQ format is similar to the YUV format.
As stated above, there are several color image formats compatible with one another. Unfortunately, a portable mobile telephone employing an RGB color display unit for displaying an RGB color image cannot display a YUV color image. For example, when it is necessary to on-screen display a 256-color RGB image received from the outside and an internally generated true-color YUV background image on the color display unit, the portable mobile telephone with the RGB color display unit cannot do so.